The invention relates generally to pipe joint assemblies, and deals more particularly with a guide sleeve which facilitates alignment of a pipe to a mating bore in a pipe joint plate.
One application for the pipe joint assembly of the present invention is to join horizontal and curved condensate-removal syphon pipes located in the interior of a dryer roller of a paper making machine. After original installation of the horizontal pipe, it must occasionally be replaced. However, only a relatively small aperture may be provided in a wall of the dryer roller to provide access to the horizontal syphon pipe and pipe joint assembly. The small size of the aperture may limit access to a single arm and the head of a work person. Also, the horizontal pipe is typically several feet long and heavy. Consequently, it has proven difficult and time consuming to align an original or replacement horizontal syphon pipe with the mating bore in the pipe joint plate. Also, the dryer roller is maintained at a high temperature during use, and it is not desirable to wait for the dryer roller to cool before replacing the pipe. Therefore, excessive replacement time discomforts the work person.
Several ways were previously known to facilitate an initial alignment between two pipes prior to joining them. For example, U.S. Pat. No. 3,345,085 to Hanes discloses an extension tube integral with an end of a pipe, which extension tube has a flared bore to receive a tapered end of a mating pipe.
U.S. Pat. No. 4,429,904 to Reimert discloses an internally threaded member having a relatively large diameter, unthreaded entrance to facilitate alignment of an externally threaded member.
U.S. Pat. No. 4,407,527 to Reimert discloses an internally threaded tubular connector which is employed to threadably join two externally threaded members. This connector includes a portion having a relatively large inside diameter to permit the initial alignment of one of the externally threaded members prior to the actual threaded engagement in the connector. The connector also includes an inwardly facing annular guide surface at the mouth of the connector and a tapered surface adjacent to the internal threads.
U.S. Pat. No. 3,520,561 to Rininger discloses a connection for pipes used in oil drilling applications. In particular, an internally threaded member includes a central protruding tube portion which is guided into an adjacent pipe prior to the threaded engagement of the two pipe members. A similar structure is disclosed in U.S. Pat. No. 3,907,335 to Burge et al.
U.S. Pat. No. 1,637,628 to Weisgerber discloses a threaded connection employing generally frusto-conical threaded members to facilitate the initial alignment.
U.S. Pat. No. 3,304,104 to Wiltse discloses a tapered lead-in to facilitate the initial connection of non-threaded tubes.
All of the foregoing patents disclose joints which are complicated and apparently expensive to produce. In addition, none of the pipe joints described in the foregoing patents is adapted to facilitate initial alignment of a pipe to a threaded bore in a pipe joint plate, nor to such a plate mounted in a vertical plane such that the bore is horizontal.
Accordingly, a general object of the present invention is to provide apparatus which facilitates the alignment of a pipe to a mating bore in a pipe joint plate.
Another general object of the present invention is to provide apparatus of the foregoing type which is simple in construction and may be readily attached to existing pipe joint plates.
A more specific object of the present invention is to provide apparatus which is specially adapted to facilitate alignment of a pipe to a horizontal bore in a pipe joint plate.